“HTTP 构建于 TCP/IP 协议之上” 这个是不正确的,HTTP 协议不限传输层,只是 URI 中的 `http` Scheme 是基于 TCP 的 HTTP。当然 TCP 也是目前最流行的 HTTP 实现。“Although HTTP is independent of the transport protocol, the "http" scheme is specific to TCP-based services because the name delegation process depends on TCP for establishing authority.” Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
“GET 请求可以被缓存,可以被收藏为书签,但 POST 不行。” POST 是可缓存的。“this specification defines GET, HEAD, and POST as cacheable” Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content
“GET 可提交的数据量受 URL 长度的限制,而 POST 的数据量则没有限制” HTTP 没有限制 URI 长度,不论是 Request Line 还是 Body 的长度限制都是实现决定,要有实现对 Body 的限制更短也是正确的。“HTTP does not place a predefined limit on the length of a request-line” Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
“HTTP messaging is independent of the underlying transport- or session-layer connection protocol(s).” 抱歉,刚刚那句找的地方不好,这句应该更清晰。Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing